Weather is probably a major factor when you plan your trip to Siuna, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and May, with an average temperature of 25°C, while the coldest months are January and February, with an average of 23°C. The rainiest months in Siuna are June, October, July and September, with each month seeing an average of 291 mm of rainfall.